Abstract Factory

Simple Factory

Strategy

Decorator

Singleton

Factory Method

Observer

Makes each

state its own class.

Delegates behavior to state objects.

Uses inheritance instead of composition.

Requires multiple if-then-else.

Defines a common State interface.

The MacroCommand class is abstract.

A macro command can only execute commands on one receiver.

A MacroCommand class implements the 'Command' Interface.

A macro command is formed by an array of single commands.

Template Method allows to vary an algorithm at runtime.

Template Method varies an algorithm.

Strategy allows to vary an algorithm at runtime.

Template

Method uses inheritance to vary part of an algorithm.

Single Responsibility Principle

Liskov Substitution Principle

Hollywood Principle

Program to an interface not an implementation

Implements the Iterable interface.

Implements the Component interface.

The hasNext() method always returns True.

The hasNext() method always returns False.

Implements the Iterator interface.

The Facade Pattern applies the Principle of Least Knowledge

The Facade Pattern encapsulates a complex subsystem.

The Facade Pattern decouple

clients and subsystem classes.